Phlebotinum Pills

Alternative Title: Phlebotimol

Applied Phlebotinum in pharmaceutical format.

Step 1: Swallow Pill
Step 2: Engage with Plot

Possible manifestations of the trope could be: drugs which induce dreaming, a cure that must be taken every so often to stave off zombification, super vitamins, orally taken miracle cures, cyanide capsules, Super Serum that must be taken twice a day with meals, etc.

Due to the stigma (it's hard to not imagine that Our Hero is basically using super 'roids), heroes who start this way tend to wind up having the method of powering up changed. You will certainly never see a hero pop a pill to power up in an Animated Adaptation.

Related to (but not the same as) Food Pills.

Examples of Phlebotinum Pills include:

Anime and Manga

Senzu Beans, which restore a person to full health.
Energy Steriods used by Hodi of One Piece.
8 Man's "radium cigarettes".

Comic Books

Miraclo, the drug that gives Hourman superpowers for an hour in The DCU.
Panacea Pills that give Vita-Man (an Alternate Company Equivalent of Hourman) powers in Big Bang Comics.
Early on, (Gi)Ant Man and the Wasp in the Marvel Universe took Pym Particle pills to grow or shrink. Now they can generate the particles at will. Animated versions of the two usually have belt or wrist devices that trigger size-changing. It should be noted that Pym Particles indeed power all versions; it's just the method of applying them that changes over the years/media.
The 'performance enhancers' that gave Demon superspeed and enhances strength and reflexes in Justice Machine.
In the original Silver Age version of the Secret Six, August Durand was kept alive by a daily pill that counteracted the deadly virus he had been infected with. Mockingbird was Durand's only source of these pills and kept Durand in line by threatening to cut off his supply.

Film

Limitless: A pill that unlocks your full potential. Nuff said.
The Matrix: "[That Red Pill] is part of a trace program." In other words, it allows you to get out of the Matrix.
Total Recall. While Doug Quaid is on Mars, a psychiatrist tries to get him to take a pill which will cause him to wake up back at Rekall. Quaid ends up spitting it out. The movie doesn't make it clear whether Quaid is hallucinating or not, so we can't be sure whether it would have worked or if it was just one of Cohaagen's tricks.
Special subverts this: Les is in a drug study for a new antidepressant, and thinks that the pills are giving him superpowers, when in reality, he's having "an adverse psychological reaction" to the drug - it's all in his head.

Literature

Spice pills are seen briefly in Dune Messiah, used by a Guild Navigator, as they rely on the spice for their limited prescience.

Live Action TV

El Chapulin Colorado's "Pastillas de Chiquitlina" (Smallinium/Shrink-o-line pills). Reduce its user to Fun Size.
Battlestar Galactica features magical pills, called chamalla, which are used by holy oracles and priests to induce visions—and which are, somehow, also a kind of cancer treatment. When cancer-ridden President Roslin starts to take them, they proceed to trigger wild prophetic hallucinations which help to chart the course of the plot for several seasons.

Tabletop Games

Champions adventure The Great Super Villain Contest. One of the NPCs, the Dash, had Energy Pills that increased his Endurance by 100 points. He needed them because his super powers had high Endurance costs.
Classic Traveller had a number of wonder drugs in convenient pill form, including anagathics (stopped the aging process), fast drug (reduced speed and metabolism to 1/60th of normal), slow drug (act twice as fast as normal), truth drug (compelled truthfulness for 2 minutes), combat drug (improved Strength and Endurance) and several drugs that enhanced psionic ability.

Video Games

The Trauma Center series has this in two flavors: phlebotonium "antibiotic" gel which is used as an antiseptic, surgical glue, or for instantly healing small lasceration and other very minor wounds (the latter property of which is lampshaded to hell and back on it's first appearance); and a phlebotonium serum know as "stabilizer" that increases the patient's vitals instantly upon being injected. The issue of why they don't just put critical patients on a drip of the stuff is Handwaved by stating it "artificially" raises vitals and is actually dangerous to use over prolonger periods.
- Additionally, these aren't even going into the various experimental serums injected into various things in specific missions.
Quintessence the Blighted Venom: Quintessence itself. While it does come in liquid form, the "consumable" (It's venom still.) kind the protagonists use is in pills.
- The pure kind, however, is apparently a liquid of some sort. But the protagonists don't have access to it.

Western Animation

Underdog's Power Energy/Energy Vitamin Pills.
Roger Ramjet's Proton Pills, which give him the power of twenty atom bombs for twenty seconds.